The influence of temperature in sea urchin embryo toxicity of crude and bunker oils alone and mixed with dispersant

This investigation deals with how temperature influences oil toxicity, alone or combined with dispersant (D). Larval lengthening, abnormalities, developmental disruption, and genotoxicity were determined in sea urchin embryos for assessing toxicity of low-energy water accommodated fractions (LEWAF) of three oils (NNA crude oil, marine gas oil -MGO-, and IFO 180 fuel oil) produced at 5-25 degrees C. PAH levels were similar amongst LEWAFs but PAH profiles varied with oil and production temperature. The sum of PAHs was higher in oil-dispersant LEWAFs than in oil LEWAFs, most remarkably at low production temperatures in the cases of NNA and MGO. Genotoxicity, enhanced after dispersant application, varied depending on the LEWAF production temperature in a different way for each oil. Impaired lengthening, abnormalities and developmental disruption were recorded, the severity of the effects varying with oil, dispersant application and LEWAF production temperature. Toxicity, only partially attributed to individual PAHs, was higher at lower LEWAF production temperatures.

Automated summary

This investigation examines the influence of temperature on oil toxicity, both alone and in combination with dispersants (D). The toxicity of low-energy water accommodated fractions (LEWAF) of three oils (NNA crude oil, marine gas oil -MGO-, and IFO 180 fuel oil) produced at temperatures ranging from 5 to 25 degrees Celsius was assessed by measuring larval lengthening, abnormalities, developmental disruption, and genotoxicity in sea urchin embryos. The levels of polycyclic aromatic hydrocarbons (PAHs) were similar among LEWAFs but the PAH profiles varied with the type of oil and production temperature. The presence of dispersants increased genotoxicity, which varied depending on the LEWAF production temperature of each oil. Impaired lengthening, abnormalities, and developmental disruption were observed, with the severity of these effects depending on the type of oil, dispersant application, and LEWAF production temperature. Toxicity, partly associated with individual PAHs, was higher at lower LEWAF production temperatures.